diff --git a/.golangci.yml b/.golangci.yml
index c3629a5b..43cb3c94 100644
--- a/.golangci.yml
+++ b/.golangci.yml
@@ -13,7 +13,7 @@ linters:
     - gocritic
     - godot
     - godox
-    - gofmt
+    - gofumpt
     - goimports
     - gomodguard
     - goprintffuncname
@@ -37,7 +37,5 @@ linters:
     - whitespace
 
 linters-settings:
-  gofmt:
-    simplify: true
   misspell:
     locale: US
diff --git a/.vscode/settings.json b/.vscode/settings.json
new file mode 100644
index 00000000..4009c66d
--- /dev/null
+++ b/.vscode/settings.json
@@ -0,0 +1,6 @@
+{
+    "go.lintTool":"golangci-lint",
+    "go.lintFlags": [
+        "--fast"
+    ]
+}
\ No newline at end of file
diff --git a/CONTRIBUTING.md b/CONTRIBUTING.md
index 07822bfd..1e0c7284 100644
--- a/CONTRIBUTING.md
+++ b/CONTRIBUTING.md
@@ -26,24 +26,15 @@ all your interactions with the project members and users.
 
 #### Process
 
-1. Essential bug fix PRs should be sent to both master and release branches.
-2. Small bug fix and feature enhancement PRs should be sent to master only.
-3. Follow the existing code style precedent, especially for C. For Golang, you
-   will mostly conform to the style and form enforced by the "go fmt" and
-   "golint" tools for proper formatting.
-4. Ensure any install or build dependencies are removed before doing a build
-   to test your PR locally.
-5. For any new functionality, please write appropriate go tests that will run
-   as part of the Continuous Integration (Circle CI) system.
-6. The project's default copyright and header have been included in any new
-   source files.
-7. Make sure you have implemented a local `make test` and all tests succeed
-   before submitting the PR.
-8. Is the code human understandable? This can be accomplished via a clear code
-   style as well as documentation and/or comments.
-9. The pull request will be reviewed by others, and finally merged when all
-   requirements are met.
-10. Documentation must be provided if necessary (next section)
+1. Essential bug fix PRs should be sent to both `master` and release branches (if applicable).
+1. Small bug fix and feature enhancement PRs should be sent to `master` only.
+1. Follow the existing code style precedent. Use [golangci-lint](https://golangci-lint.run) to ensure your code is properly formatted and free of lint.
+1. For any new functionality, please write appropriate tests that will run as part of the continuous integration system ([CircleCI](https://circleci.com/gh/sylabs/workflows/sif)).
+1. Ensure the project's default copyright and header have been included in any new source files.
+1. Make sure you have run `go test ./...` and all tests succeed before submitting the PR.
+1. Is the code human understandable? This can be accomplished via a clear code style as well as documentation and/or comments.
+1. The pull request will be reviewed by others, and finally merged when all requirements are met.
+1. Documentation must be provided if necessary (next section)
 
 #### Documentation
 
diff --git a/cmd/siftool/modif.go b/cmd/siftool/modif.go
index ba439a9d..34a3490b 100644
--- a/cmd/siftool/modif.go
+++ b/cmd/siftool/modif.go
@@ -1,4 +1,4 @@
-// Copyright (c) 2018, Sylabs Inc. All rights reserved.
+// Copyright (c) 2018-2021, Sylabs Inc. All rights reserved.
 // This software is licensed under a 3-clause BSD license. Please consult the
 // LICENSE file distributed with the sources of this project regarding your
 // rights to use or distribute this software.
@@ -14,16 +14,18 @@ import (
 	"github.com/sylabs/sif/pkg/sif"
 )
 
-var datatype = flag.Int64("datatype", -1, "")
-var parttype = flag.Int64("parttype", -1, "")
-var partfs = flag.Int64("partfs", -1, "")
-var partarch = flag.Int64("partarch", -1, "")
-var signhash = flag.Int64("signhash", -1, "")
-var signentity = flag.String("signentity", "", "")
-var groupid = flag.Int64("groupid", sif.DescrUnusedGroup, "")
-var link = flag.Int64("link", sif.DescrUnusedLink, "")
-var alignment = flag.Int("alignment", 0, "")
-var filename = flag.String("filename", "", "")
+var (
+	datatype   = flag.Int64("datatype", -1, "")
+	parttype   = flag.Int64("parttype", -1, "")
+	partfs     = flag.Int64("partfs", -1, "")
+	partarch   = flag.Int64("partarch", -1, "")
+	signhash   = flag.Int64("signhash", -1, "")
+	signentity = flag.String("signentity", "", "")
+	groupid    = flag.Int64("groupid", sif.DescrUnusedGroup, "")
+	link       = flag.Int64("link", sif.DescrUnusedLink, "")
+	alignment  = flag.Int("alignment", 0, "")
+	filename   = flag.String("filename", "", "")
+)
 
 func cmdNew(args []string) error {
 	if len(args) != 1 {
diff --git a/pkg/integrity/verify.go b/pkg/integrity/verify.go
index 83a292b1..2fd9adde 100644
--- a/pkg/integrity/verify.go
+++ b/pkg/integrity/verify.go
@@ -58,6 +58,7 @@ func (e *SignatureNotValidError) Is(target error) bool {
 	return e.ID == t.ID || t.ID == 0
 }
 
+// VerifyResult is the interface that each verification result implements.
 type VerifyResult interface {
 	// Signature returns the ID of the signature object associated with the result.
 	Signature() uint32
@@ -520,7 +521,7 @@ func OptVerifyCallback(cb VerifyCallback) VerifierOpt {
 }
 
 // getTasks returns verification tasks corresponding to groupIDs and objectIDs.
-func getTasks(f *sif.FileImage, cb VerifyCallback, groupIDs []uint32, objectIDs []uint32) ([]verifyTask, error) {
+func getTasks(f *sif.FileImage, cb VerifyCallback, groupIDs, objectIDs []uint32) ([]verifyTask, error) {
 	t := make([]verifyTask, 0, len(groupIDs)+len(objectIDs))
 
 	for _, groupID := range groupIDs {
@@ -548,7 +549,7 @@ func getTasks(f *sif.FileImage, cb VerifyCallback, groupIDs []uint32, objectIDs
 }
 
 // getLegacyTasks returns legacy verification tasks corresponding to groupIDs and objectIDs.
-func getLegacyTasks(f *sif.FileImage, cb VerifyCallback, groupIDs []uint32, objectIDs []uint32) ([]verifyTask, error) {
+func getLegacyTasks(f *sif.FileImage, cb VerifyCallback, groupIDs, objectIDs []uint32) ([]verifyTask, error) {
 	t := make([]verifyTask, 0, len(groupIDs)+len(objectIDs))
 
 	for _, groupID := range groupIDs {
diff --git a/pkg/integrity/verify_test.go b/pkg/integrity/verify_test.go
index 3dc9e105..9289f559 100644
--- a/pkg/integrity/verify_test.go
+++ b/pkg/integrity/verify_test.go
@@ -1,4 +1,4 @@
-// Copyright (c) 2020, Sylabs Inc. All rights reserved.
+// Copyright (c) 2020-2021, Sylabs Inc. All rights reserved.
 // This software is licensed under a 3-clause BSD license. Please consult the LICENSE.md file
 // distributed with the sources of this project regarding your rights to use or distribute this
 // software.
@@ -903,6 +903,7 @@ type mockVerifier struct {
 func (v mockVerifier) fingerprints() ([][20]byte, error) {
 	return v.fps, v.err
 }
+
 func (v mockVerifier) verifyWithKeyRing(kr openpgp.KeyRing) error {
 	return v.err
 }
diff --git a/pkg/sif/create.go b/pkg/sif/create.go
index e06eef4a..98ec9264 100644
--- a/pkg/sif/create.go
+++ b/pkg/sif/create.go
@@ -1,4 +1,4 @@
-// Copyright (c) 2018-2020, Sylabs Inc. All rights reserved.
+// Copyright (c) 2018-2021, Sylabs Inc. All rights reserved.
 // Copyright (c) 2017, SingularityWare, LLC. All rights reserved.
 // Copyright (c) 2017, Yannick Cote <yhcote@gmail.com> All rights reserved.
 // This software is licensed under a 3-clause BSD license. Please consult the
@@ -237,7 +237,7 @@ func CreateContainer(cinfo CreateInfo) (fimg *FileImage, err error) {
 	fimg.Header.Dataoff = DataStartOffset
 
 	// Create container file
-	fimg.Fp, err = os.OpenFile(cinfo.Pathname, os.O_RDWR|os.O_CREATE|os.O_TRUNC, 0755)
+	fimg.Fp, err = os.OpenFile(cinfo.Pathname, os.O_RDWR|os.O_CREATE|os.O_TRUNC, 0o755)
 	if err != nil {
 		return nil, fmt.Errorf("container file creation failed: %s", err)
 	}
diff --git a/pkg/sif/create_test.go b/pkg/sif/create_test.go
index 52ee6876..99e2fadb 100644
--- a/pkg/sif/create_test.go
+++ b/pkg/sif/create_test.go
@@ -382,7 +382,7 @@ func cpFile(fromFile, toFile string) error {
 	}
 	defer s.Close()
 
-	d, err := os.OpenFile(toFile, os.O_CREATE|os.O_TRUNC|os.O_WRONLY, 0777)
+	d, err := os.OpenFile(toFile, os.O_CREATE|os.O_TRUNC|os.O_WRONLY, 0o777)
 	if err != nil {
 		return err
 	}
diff --git a/pkg/sif/load_test.go b/pkg/sif/load_test.go
index cc52385e..1e5860eb 100644
--- a/pkg/sif/load_test.go
+++ b/pkg/sif/load_test.go
@@ -76,7 +76,7 @@ func (m *mockFileInfo) Size() int64 {
 }
 
 func (m *mockFileInfo) Mode() os.FileMode {
-	return 0644
+	return 0o644
 }
 
 func (m *mockFileInfo) ModTime() time.Time {
diff --git a/pkg/sif/lookup.go b/pkg/sif/lookup.go
index d0c8b02c..2cb1ab16 100644
--- a/pkg/sif/lookup.go
+++ b/pkg/sif/lookup.go
@@ -77,7 +77,7 @@ func (fimg *FileImage) GetHeader() *Header {
 
 // GetFromDescrID searches for a descriptor with.
 func (fimg *FileImage) GetFromDescrID(id uint32) (*Descriptor, int, error) {
-	var match = -1
+	match := -1
 
 	for i, v := range fimg.DescrArr {
 		if !v.Used {
diff --git a/pkg/sif/sif.go b/pkg/sif/sif.go
index 09c05a78..08f8d0ac 100644
--- a/pkg/sif/sif.go
+++ b/pkg/sif/sif.go
@@ -316,16 +316,13 @@ type Descriptor struct {
 }
 
 // Deffile represents the SIF definition-file data object descriptor.
-type Deffile struct {
-}
+type Deffile struct{}
 
 // Labels represents the SIF JSON-labels data object descriptor.
-type Labels struct {
-}
+type Labels struct{}
 
 // Envvar represents the SIF envvar data object descriptor.
-type Envvar struct {
-}
+type Envvar struct{}
 
 // Partition represents the SIF partition data object descriptor.
 type Partition struct {
@@ -341,12 +338,10 @@ type Signature struct {
 }
 
 // GenericJSON represents the SIF generic JSON meta-data data object descriptor.
-type GenericJSON struct {
-}
+type GenericJSON struct{}
 
 // Generic represents the SIF generic data object descriptor.
-type Generic struct {
-}
+type Generic struct{}
 
 // CryptoMessage represents the SIF crypto message object descriptor.
 type CryptoMessage struct {
diff --git a/pkg/siftool/siftool.go b/pkg/siftool/siftool.go
index 7bc526ff..12d41649 100644
--- a/pkg/siftool/siftool.go
+++ b/pkg/siftool/siftool.go
@@ -1,4 +1,4 @@
-// Copyright (c) 2018-2019, Sylabs Inc. All rights reserved.
+// Copyright (c) 2018-2021, Sylabs Inc. All rights reserved.
 // Copyright (c) 2017, SingularityWare, LLC. All rights reserved.
 // Copyright (c) 2017, Yannick Cote <yhcote@gmail.com> All rights reserved.
 // This software is licensed under a 3-clause BSD license. Please consult the
@@ -31,7 +31,7 @@ func Siftool() *cobra.Command {
 	// A set of commands are provided to display elements such as the SIF global
 	// header, the data object descriptors and to dump data objects. It is also
 	// possible to modify a SIF file via this tool via the add/del commands.
-	var Siftool = &cobra.Command{
+	Siftool := &cobra.Command{
 		Use:                   "sif",
 		Short:                 "siftool is a program for Singularity Image Format (SIF) file manipulation",
 		Long:                  siftoolLong,